in vitro

American  

[in vee-troh] / ɪn ˈvi troʊ /

adverb

1. (of a biological process) made to occur in a laboratory vessel or other controlled experimental environment rather than within a living organism or natural setting.

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in vitro British  

/ ɪn ˈviːtrəʊ /

adverb

1. (of biological processes or reactions) made to occur outside the living organism in an artificial environment, such as a culture medium

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in vitro Scientific  

/ ĭnvē′trō /

1. In an artificial environment, such as a test tube.

2. Compare in vivo

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in vitro Cultural  

1. In the laboratory; literally, “in glass” (laboratory experiments are often carried out in glass containers). In vitro conditions are distinguished from conditions that actually apply in nature. (Compare in vivo.)

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Discover More

In vitro appears in the expression in vitro fertilization , a way of producing human embryos in a laboratory.

Etymology

Origin of in vitro

First recorded in 1890–95; from Latin in vitrō, literally, “in glass”

Compare meaning

How does in-vitro compare to similar and commonly confused words? Explore the most common comparisons:

• in vivo vs. in vitro

Example Sentences

In these in vitro reconstitution experiments, they observed that the filaments display dynamic instability.

From Science Daily • Apr. 20, 2026

Last March, at a Women’s History Month event, President Donald Trump highlighted his record on women’s health, including support for in vitro fertilization, saying he’ll one day be known as the “fertilization president.”

From Salon • Apr. 18, 2026

Fertility treatments: Large employer health plans will be required to cover infertility treatments, including in vitro fertilization, for everyone, regardless of marital status, gender identity or sexual orientation.

From Los Angeles Times • Jan. 1, 2026

Nelson was still married in 2020 when the fertility clinic called her at work with devastating news: Her husband had just requested the destruction of the embryos they created through in vitro fertilization, or IVF.

From The Wall Street Journal • Nov. 23, 2025

When that didn’t work, he recommended we move to in vitro fertilization.

From "Becoming" by Michelle Obama